LONDON, Oct 12 British Prime Minister Theresa
May said on Wednesday parliament would have every opportunity to
debate her government's plans to leave the European Union, but
ruled out letting it vote on triggering the formal Brexit
procedure.

May has been under pressure to divulge more of her plans for
Britain's exit from the bloc beyond her catchphrase that "Brexit
means Brexit", but in a lively session of parliament her
government said it had little concrete to give away.

Uncertainty over what kind of deal Britain will pursue in
some of the most complex talks it has undertaken since World War
Two has unsettled investors and markets.

The British currency is particularly sensitive to any
suggestion that the country might be heading towards a "hard
Brexit", or a clean break from the EU's single market of 500
million consumers in order to control immigration.

Sterling, which has lost 18 percent against the dollar since
the June Brexit referendum, rallied on reports that parliament
would get to vote on May's deal, but eased slightly after her
spokeswoman said there would be no vote on triggering Article 50
of the EU's Lisbon Treaty. This starts the formal negotiation
process, lasting up to two years, until Britain's departure.

"The idea that parliament somehow wasn't going to be able to
discuss, debate, question ... was frankly completely wrong," May
said when asked by an opposition Labour lawmaker whether
parliament would get a vote on the government's Brexit plan.

"Parliament is going to have every opportunity to debate
this issue."

Increasingly conscious that markets are moving on her words,
May was clear that she would be "ambitious" in talks with the
other 27 EU members to get what she called the best deal.

"And that will include the maximum possible access to the
European market for firms to trade with and operate within," May
told parliament, a statement which helped sterling gain around a
quarter of a cent against the dollar.

UNDER PRESSURE

Appointed prime minister shortly after the June 23 vote on
EU membership, replacing David Cameron who resigned, May has
come under pressure to drop her insistence that she will not
give a "running commentary" on the Brexit negotiations.

By refusing to debate her strategy, lawmakers say, May is
undermining Britain's centuries-old parliamentary democracy. May
says she does not want to show her hand before the talks.

"How are you going to build a consensus around your approach
if you won't tell this house what your approach is?" Labour
Brexit spokesman Keir Starmer said. "The mandate on the 23rd of
June was not a mandate on the terms (of a Brexit deal)."

Labour demanded Wednesday's debate and May accepted on
condition that it would not undermine her negotiating strategy.

May, a former interior minister, has defended her
"prerogative" to trigger the departure without parliamentary
approval and her government will defend that position at
London's High Court on Thursday, when a legal challenge led by a
pro-EU investment fund manager will begin.

Investors fear that, with three leading Brexit campaigners
among her closest advisers, May is taking Britain towards a
"hard Brexit". On Tuesday, several senior bankers said they
could start moving staff abroad as early as next year if there
was no clarity on access to the single market.

Brexit minister David Davis told parliament the government
was not yet in a position to provide details of what it wanted
from the talks beyond its "overarching aims".

He said the talk of "soft" and "hard" Brexit should be
avoided because there was "a spectrum" of options for Britain as
it negotiated its exit from the bloc that it joined in 1973.

"The overarching aims are these: bringing back control of
laws to parliament, bringing back control over decisions of
immigration to the UK, maintaining the strong security
cooperation that we have with the European Union and
establishing the freest possible market in goods and services
with the European Union and the rest of the world," he said.

"We have been pretty clear on the overarching aims, not the
detailed aims. We're not even at the point that that's
possible," Davis added.
(additional reporting by Kylie MacLellan, William James, Peter
Hobson, editing by Peter Millership and Gareth Jones)